i have an application that has to return emails to a user with his email client, but in some cases I have to pass around 1000 emails.
I'm using mailto on href, something like this:
mailto:info@useremail.com?bcc=email1@test.com,email2@other.net,anotherone@dfsf...
Why am I returning to his email client instead using PHP mail() function?
Because the user sender email depends on which computer he is using, and he needs to archive thoose emails.
The problem: Some browsers, if the email list is bigger than X, it won't send to his preferred email client.
You could output the full BCC list and ask the user to copy-paste it in. But maybe you should just rethink your entire strategy if you want to pass thousands of e-mail addresses to a user.